1. Field of the Invention
The present invention relates to footwear and more particularly to a clasp for detachably securing an upper, such as strap, to an outsole, to permit uppers to be interchanged to alter the appearance of the footwear.
2. Description of Prior Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
This application is a continuation of copending application Ser. No. 11/000,879, filed Dec. 1, 2004, entitled: “Locking Mechanism for Securing Detachable Shoe Uppers” which is hereby incorporated herein by reference.
The desirability of being able to change the appearance of footwear, for example sandals or high heel soles, by interchanging the uppers, usually in the form of straps, bands or the like, is well documented in the art. However, to be commercially successful, the ends of the upper must be able to be connected to the outsole in a secure manner that permits easy attachment and detachment and, at the same time, does not interfere with the comfort of the wearer. Further, it is desirable that the connecting system be useable with standard outsoles because the design, fabrication and inventorying of customized outsoles for this purpose adds considerable expense to the product.
It is known, for example, to use an attachment system in which one part pushed down into a recess formed in the outsole. That system is undesirable because it cannot be made to withstand the forces involved and because the outsoles must be customized for this purpose.
Another system that has been used is to form a channel in the outsole into which a part attached to the end of the strap is slideably received. Here again strength may be an issue and the outsole must be customized. Further, the outsole must be made wider than usual to accommodate the foot, and hence may not be appropriate for certain types of footwear, particularly high fashion dress shoes for women.
Others have attempted to use various types of connecting mechanisms that include detachable parts, one of which is fixed to the outsole. However, if made strong enough to withstand the forces involved, those mechanisms tend to make the footwear uncomfortable to wear because they create a bulge under the foot or rub against the side of the foot as the user walks.